When publishing newspapers covering a wide geographic region, for example, national newspapers, images and so forth for each page are edited at the newspaper's head office, and then the results of the editing work are supplied in the form of multivalued image data. This multivalued image data is subjected to RIP processing (Raster Image Processing) at the newspaper head office to form binary image data, and this binary image data is transmitted to each newspaper printing factory. In the system used, for example, in the case of color pages, binary image data (dot data or bitmapped page image information) for each of the colors CMYB (cyan, magenta, yellow, and black) is transmitted from the newspaper company to each newspaper printing factory located in each region.
At each newspaper printing factory which receives the binary image data, in a print management system, operations are performed for inputting corresponding page indexes (codes etc. related to the version name, page, and color) and information about the newspaper press to be used etc. into the binary image data for each page, as well as for applying inspection marks and cut-off marks to the binary image data for each page.
When binary image data for each page is completed in this way, platemaking is performed on the basis of the respective binary image data. Platemaking is performed by, for example, CTP (Computer to Plate) equipment or CTF (Computer to Film) equipment. The plates created in this way are manually mounted on the plate cylinders of corresponding newspaper presses by an operator, and then printing is carried out on each newspaper press.
In this kind of newspaper printing, it is known that there are inevitably differences in the color and so on of the printed matter due to the various types of printing materials (printing paper, ink, etc.), individual differences among newspaper presses, and so forth. Thus, to match the colors of the printed matter between newspaper presses, color management has been proposed in the related art (for example, see Patent Document 1).
For example, the color management disclosed in Patent Document 1 is carried out by the following procedure.
First, the newspaper company transmits multivalued image data instead of binary image data. Each newspaper printing factory holds color management information for each newspaper press installed in the factory, and the multivalued image data is color corrected using this color management information. Accordingly, multivalued image data reflecting the characteristics of each newspaper press is created for each newspaper press. Then, the color-corrected multivalued image data is converted to binary image data by RIP processing, and printing is performed on the basis of this binary image data.    Patent Document 1: Japanese Unexamined Patent Application, Publication No. 2004-351929.